Re: NSComparator - sorting objects in a NSMutableArray

Hi Matt,

Matt Kime wrote:
> I have an NSMutableArray populated with objects. I want do sort them
> based on a double type property. sortUsingComparator seems to be the
> way to go. this means i need to implement a "compare" function in the
> object.
> 
> this is the first time i'm tackling this technique and i'm finding
> the javadocs too terse to understand. does anyone know where i can
> find an example of this?
> 

This might help.
http://java.sun.com/j2se/1.4.2/docs/api/java/lang/Comparable.html

I think the following will work.. However I just wrote it and havent 
tried it so it probably will have something(s) wrong.  :)

public int compare(Object o1, Object o2)
     throws NSComparator.ComparisonException {

   if (! (o1 instanceof o2) ) {
       throw new NSComparator.ComparisonException(
                 "null reference or wrong class");
   }

   double d1 = ((MyObject)o1).myDouble;
   double d2 = ((MyObject)o2).myDouble;

   if (d1 == d2) return NSComparator.OrderedSame;
   if (d1 < d2 ) return NSComparator.OrderAscending;
   return NSComparator.OrderDescending;
}


cheers,
  - shaun